This invention relates to a hydrogen production plant using a reformer to supply hydrogen to a hydrogen compressor, and in particular, to a hydrogen production plant using an electrochemical autothermal reformer (EATR) to provide hydrogen fuel to an electrochemical hydrogen compressor (EHC).
An EHC is essentially a fuel cell operated in reverse. A fuel cell is an electrochemical cell that converts the chemical energy of a fuel directly into electric energy in a continuous process. The fuel cell's overall reaction typically involves the combination of hydrogen with oxygen to form water. For example, at 25.degree. C. and 1 atm pressure, the reaction H.sub.2 +1/2O.sub.2 .fwdarw.H.sub.2 O takes place with a free energy change (.DELTA.G) of -56.69 kcal/mole. In a galvanic cell, this reaction produces a theoretical cell voltage of 1.23 volts. Actual values are typically within the range of 0.9 to 1.1 volts. The main types of fuel cells used today are the proton exchange membrane or solid polymer electrolyte fuel cell, phosphoric acid fuel cell, alkaline fuel cell, solid oxide fuel cell, and molten carbonate fuel cell. Details on these individual technologies is found in "Fuel Cells, A Handbook (Revision 3)" published January, 1994 by the U.S. Department of Energy Office of Fossil Energy, incorporated herein in its entirety by reference.
The EHC is an electrochemical cell that converts electric energy directly to chemical energy in a continuous process. Instead of placing a load across the anode and cathode sections in a fuel cell to produce electricity, in the EHC, an external power supply is placed across the anode and cathode sections to reverse the process. Hydrogen accumulates in the cathode. Thus, an EHC needs two major inputs to function: hydrogen from a source and an externally applied voltage.